At present, breaking of a high voltage DC current can only satisfy the need of load current transformation in a point-to-point type DC transmission substation, but cannot break a short-circuit fault current at a system voltage yet; besides, breaking speed is also limited to a certain extent. Studies have shown that high-voltage DC short-circuit breaking based on methods of self-excited oscillation zero crossing, forced oscillation zero crossing and hybrid breaking have many pending difficulties to address, such that people are still unclear about the main theoretical fundaments that affect high-voltage DC breaking capacity and breaking speed. At the same time, since focus on the short-circuit current high-voltage DC breaking technologies is not enough, and relevant experimental data and experience accumulation is also insufficient; researchers in the industry have to rely on repeated tests for product development, which significantly delays the development progress, increases cost, and restricts product design optimization and performance enhancement. Therefore, it is an urgent task to launch relevant studies on high-voltage DC breaking technologies.
A typical hybrid circuit breaker utilizes a full-controlled power electronic device to realize rapid transfer and current breaking; however, the cost is expensive and a complex water cooling system is required, such that it is difficult to promote in future high voltage DC systems. In order to reduce usage of the full-controlled power electronic devices, an arc-free DC circuit breaker combining magnetic induction transfer and resistive current-limiting is provided. By using an induction module to quickly transfer current to capacitors and resistors, on the one hand, fast switching arc-free opening may be achieved and voltage withstanding capability of the break(er) is improved; on the other hand, current may be limited under a certain level through resistive current-limiting, and the current turn-off is achieved through an IGBT device. Usage of such circuit breaker IGBT devices can be significantly reduced to 25% of the conventional circuit breaker; besides, without the need of a complex cooling system, it has advantages such as a fast transfer speed, a strong voltage-withstanding capability, a high reliability and the like, and thus has a high feasibility.